This invention relates to locksmithing equipment, and is more particularly directed to a device for automatically finding the opening combination for the combination lock of a secure cabinet, safe, or vault. The invention is more particularly directed to apparatus that can employ a "manipulation" technique, i.e., by sensing the dial position of so-called contact points, and automatically dialing to the contact points to determine the digits or numbers, and the proper sequence, of the opening combination.
It sometimes occurs that the combination to a safe, cabinet, or vault is forgotten or lost, or is simply not available and not recorded. In such cases, it is up to the skill of the individual locksmith to open the safe. Even under ideal circumstances, where the locksmith is familiar with the safes and locks of the same manufacturer, and where one or more numbers of the combination may be known, it is still a difficult, time consuming, and frustrating task to decode the opening combination. In some cases, particularly where the workings of the lock mechanism are old and not understood, the locksmith may drill into the lock assembly to permit visual manipulation of the rotor, wheels, or tumblers and the associated release mechanism of the lock. Of course, where drilling into the safe or vault is required, it is usually necessary to replace the lock, and, in any event, the drill holes must be welded shut before the safe can be used again. Invariably, finding the opening combination of a safe or vault is an extremely difficult and frustrating activity, even for the most experienced locksmiths.
The so-called manipulation technique is a manual, nondestructive procedure, in which, without the use of sophisticated tools or equipment, the locksmith senses, either audibly or by feel, the so-called "contact" points. The position of the contact points has to be determined very accurately, that is, to within about the nearest tenth of a digit or number on the dial. The exact reading of the contact point is recorded where it is reached from each of a number of starting positions around the dial. These readings are charted and low or high spots are scrutinized to yield the opening number for one of the several rotors or wheels of the lock. Then a test is run to see whether it is the number one, two, or three wheel that indicated. This procedure is repeated until the opening number for each of the wheels is learned.
Manipulation is an involved, tedious procedure, and it requires a high degree of skill and considerable background experience. The procedure can be expected to take one full day or more for a skilled locksmith working without interruption.
This technique is well-known in the locksmithing trade. A description of one version of a manipulation technique is contained in David Gilliam, "Safe Lock Manipulation Simplified," New York School of Locksmithing, 1975.
While no special equipment is required, many locksmiths use a stethoscope or other listening device to listen for the contact points. Special scales, magnifiers, and special lighting are sometimes employed to help the locksmith find the location of contact points to within a small fraction of the spacing between successive dial digits.
There has been proposed a combination of an electro-optical dial position sensor and a sensitive microphone for indicating the position of contact points, specifically to assist the locksmith in manually manipulating the safe lock. One such manipulation aid is described in Armstrong, "Manipulation? It's A Breeze!", Locksmith Ledger, March 1988. Even with this type of aid, there is still room for human error, and it still requires considerable time for a highly experienced locksmith to open the safe.
Because of difficulties in accurately sensing the contact points, the manipulation technique does not work every time on all types of safes and locks. Extreme care must be exercised in rotating the dial at a steady rate and with even hand pressure. Thus, it is difficult to manipulate old locks, or locks with loose or sticky dials. It is also extremely difficult and time consuming to open a so-called manipulation-proof lock, which incorporates some feature for defeating attempts to find the contact points. While even a manipulation proof lock can be subjected successfully to a manipulation technique, additional steps are required, and consequently the time and difficulty in opening this type of lock are several times that required for other locks.
In my previous U.S. Pat. No. 4,433,563, I disclosed a safe opening apparatus which would automatically, and unattended, decode a safe lock combination. This device, however, did not employ manipulation, but rather worked all possible safe combinations until the safe lock opened. There were three innovative processes employed by this device. First, it did not try "illegal" combinations. Secondly, it skipped every two numbers before trying the combination. Third, it adjusted only the necessary tumblers when dialing new combinations. The device included means to detect when the opening combination had been reached. However, the device required an amount of time related to the exponential of the number of tumblers or wheels, as it could not determine each number of the opening combination independently. Inherently, the device had to solve all of the numbers at the same time. While this device did not require the continued presence of the locksmith, typically it still required several days of continuous running to find the lost combination.
The previous device also was not sensitive enough to sense degrees of rotation less than 1/100 of a dial rotation, and would not lend itself easily to modification to make it suitable for use in automatic safe manipulation.